U.S. patent application number 12/549071 was filed with the patent office on 2011-03-03 for fan assembly.
Invention is credited to Bradley T. Fanton, ROY DAVID FULAYTER.
Application Number | 20110052398 12/549071 |
Document ID | / |
Family ID | 42352210 |
Filed Date | 2011-03-03 |
United States Patent
Application |
20110052398 |
Kind Code |
A1 |
FULAYTER; ROY DAVID ; et
al. |
March 3, 2011 |
FAN ASSEMBLY
Abstract
A fan assembly is disclosed herein. The fan assembly includes a
fan operable to rotate about an axis. The fan includes a hub and a
plurality of blades extending radially from the hub relative to the
axis. The fan also includes a reinforcing member positioned
adjacent to the fan along the axis. The reinforcing member contacts
a predetermined subset of less than all of the plurality of
blades.
Inventors: |
FULAYTER; ROY DAVID; (Avon,
IN) ; Fanton; Bradley T.; (Plainfield, IN) |
Family ID: |
42352210 |
Appl. No.: |
12/549071 |
Filed: |
August 27, 2009 |
Current U.S.
Class: |
416/219R ;
29/889.21; 416/204R |
Current CPC
Class: |
Y10T 29/49321 20150115;
F05D 2260/961 20130101; F01D 5/16 20130101; F04D 29/666 20130101;
F05D 2260/96 20130101; F04D 29/668 20130101; F04D 29/324 20130101;
F04D 29/327 20130101 |
Class at
Publication: |
416/219.R ;
29/889.21; 416/204.R |
International
Class: |
F01D 5/30 20060101
F01D005/30; B23P 11/00 20060101 B23P011/00 |
Claims
1. A fan assembly comprising: a fan operable to rotate about an
axis and including a hub and a plurality of blades extending
radially from said hub relative to said axis; and a reinforcing
member positioned adjacent to said fan along said axis and
contacting a predetermined subset of less than all of said
plurality of blades.
2. The fan assembly of claim 1 wherein each of said predetermined
subset of blades is longer along said axis than each of the
remaining blades.
3. The fan assembly of claim 1 wherein said plurality of blades are
circumferentially spaced from one another about said hub and
wherein said reinforcing member contacts every other blade.
4. The fan assembly of claim 1 wherein said reinforcing member
contacts less than half of said plurality of blades.
5. The fan assembly of claim 1 wherein said reinforcing member
further comprises: a plate portion operable to seal against said
fan; and one or more arms projecting along said axis from said
plate portion to a distal end contacting at least one of said
predetermined subset of blades.
6. The fan assembly of claim 5 wherein said plate portion and said
one or more arm are integrally-formed with respect to one
another.
7. The fan assembly of claim 1 further comprising: a quantity of
lubricating material positioned between said reinforcing member and
said predetermined subset of blades.
8. The fan assembly of claim 1 wherein said reinforcing member
contacts said fan at respective axial ends of platforms of said
predetermined subset of blades.
9. The fan assembly of claim 1 wherein said reinforcing member
contacts said fan at respective radially inward sides of platforms
of said predetermined subset of blades.
10. The fan assembly of claim 1 wherein said reinforcing member is
resiliently deformed by engagement with said fan such that a
pressing load is generated on said fan.
11. A method comprising the steps of: rotating a fan including a
hub and a plurality of blades extending radially from the hub about
an axis; and positioning a reinforcing member adjacent to the fan
along the axis such that the reinforcing member contacts a
predetermined subset of less than all of the plurality of
blades.
12. The method of claim 11 wherein said positioning step is further
defined as: reinforcing less than all of the plurality of blades to
increase the stiffness of only the reinforced blades.
13. The method of claim 11 further comprising the step of: sealing
the fan with the reinforcing member.
14. The method of claim 11 wherein said positioning step includes
the step of: contacting at least some axially aft edges of
platforms of each of the predetermined subset of blades with an
outer diameter of the reinforcing member.
15. The method of claim 11 wherein said positioning step includes
the step of: contacting at least some of the predetermined subset
of the blades radially inward of the respective platforms with the
reinforcing member.
16. The method of claim 11 wherein said positioning step includes
the step of: extending a cantilevered arm of the reinforcing member
to each of the predetermined subset of blades.
17. A turbine engine comprising: a fan operable to rotate about a
centerline axis and including a hub defining a plurality of slots
and a plurality of blades extending radially from said hub and each
received in one of said plurality of slots; a spinner body
connected to a forward side of said hub; and a reinforcing member
positioned adjacent to an aft side of said fan along said
centerline axis and contacting a predetermined subset of less than
all of said plurality of blades.
18. The turbine engine of claim 17 wherein platforms of each of
said predetermined subset of blades is longer along said axis than
each of the remaining blades and wherein an outer diameter of said
reinforcing member presses against respective axially aft ends of
said platforms.
19. The turbine engine of claim 17 wherein said reinforcing member
further comprises: a plate portion operable to seal against said
fan and prevent aft movement of each of the plurality of blades;
and a plurality of arms projecting from said plate portion along
said centerline axis to respective distal ends, each distal
contacting at least one of said predetermined subset of blades.
20. The turbine engine of claim 17 wherein each of said plurality
of arms includes a shaft portion extending from said plate portion
and a protuberance at said distal end thicker than said shaft
portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to varying the frequency of the blades
of a fan assembly.
[0003] 2. Description of Related Prior Art
[0004] U.S. Pat. No. 7,252,481 is entitled "Natural Frequency
Tuning of Gas Turbine Engine Blades." The '481 patent discloses a
blade referenced at 32 in FIG. 2. The blade 32 includes a blade
root referenced at 42. A tuning notch referenced at 50 is defined
in the back of a blade root 42 to tune the natural frequency of the
blade 32.
SUMMARY OF THE INVENTION
[0005] In summary, the invention is a fan assembly. The fan
assembly includes a fan operable to rotate about an axis. The fan
includes a hub and a plurality of blades extending radially from
the hub relative to the axis. The fan also includes a reinforcing
member positioned adjacent to the fan along the axis. The
reinforcing member contacts a predetermined subset of less than all
of the plurality of blades.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0007] FIG. 1 is a simplified cross-section of a turbine engine
according to an embodiment of the invention;
[0008] FIG. 2 is a cross-section of a fan shown schematically in
FIG. 1
[0009] FIG. 3 is an enlarged portion of FIG. 2; and
[0010] FIG. 4 is cross-section similar to FIG. 3 but of a second
embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0011] A plurality of different embodiments of the invention is
shown in the Figures of the application. Similar features are shown
in the various embodiments of the invention. Similar features have
been numbered with a common reference numeral and have been
differentiated by an alphabetic suffix. Also, to enhance
consistency, the structures in any particular drawing share the
same alphabetic suffix even if a particular feature is shown in
less than all embodiments. Similar features are structured
similarly, operate similarly, and/or have the same function unless
otherwise indicated by the drawings or this specification.
Furthermore, particular features of one embodiment can replace
corresponding features in another embodiment or can supplement
other embodiments unless otherwise indicated by the drawings or
this specification.
[0012] The invention, as exemplified in the embodiments described
below, can be applied to improve the efficiency of a turbine
engine. The efficiency can be improved by reducing the impact of
fan blade flutter. Flutter occurs when the energy associated with a
fluid stream is extracted from the fluid stream and expended in the
form of vibration of a working member disposed in the fluid stream.
The blades can also enjoy longer life if flutter is reduced since
high cycle fatigue would be reduced.
[0013] Referring to FIG. 1, a turbine engine 10 can include an
inlet 12 and a fan 14. The exemplary fan 14 can be a bladed disk
assembly having a disk or hub defining a plurality of slots and a
plurality of fan blades, each fan blade received in one of the
slots. The turbine engine can also include a compressor section 16,
a combustor section 18, and a turbine section 20. The turbine
engine 10 can also include an exhaust section 22. The fan 14,
compressor section 16, and turbine section 20 are all arranged to
rotate about a centerline axis 24. Fluid such as air can be drawn
into the turbine engine 10 as indicated by the arrow referenced at
26. The fan 14 directs fluid to the compressor section 16 where it
is compressed. The compressed fluid is mixed with fuel and ignited
in the combustor section 18. Combustion gases exit the combustor
section 18 and flow through the turbine section 20. Energy is
extracted from the combustion gases in the turbine section 20.
[0014] A nose cone assembly 28 can be attached to the fan 14. As
set forth above and shown in FIG. 2, the exemplary fan 14 can be a
bladed disk assembly having a disk or hub 30 defining a plurality
of slots. A spinner body 34 of the nose cone assembly 28 can be
attached to the hub 30. The bladed disk assembly 14 can also
include a plurality of fan blades 32. Each fan blade 32 can be
received in one of the slots of the hub 30. The blades 32 are
circumferentially spaced from one another about the axis 24 (shown
in FIG. 1). Each blade 32 can include an airfoil portion 36
extending into the flow path, a platform 38 that can be flush with
the spinner body 34, and a root portion 40 received in the slot of
the hub 30. The platform defines the inner boundary of the flow
path.
[0015] A front retainer 42 can connect the spinner body 34 and the
hub 30 together and also prevent forward movement of the blades 32.
A seal plate 44 can be fixed to the hub 30 on the aft side of the
blades 32 and prevent aft movement of the blades 32. In the
exemplary embodiments of the invention, the seal plate 44 can
define a reinforcing member for the blades to change the natural
frequency of less than all of the blades 32. The fan 14 and seal
plate 44 can together define a fan assembly according to an
embodiment of the invention. However, it is noted that in other
embodiments of the invention a structure other than a seal plate
can be applied to contact and stiffen less than all of the blades
32.
[0016] As set forth above, the exemplary fan 14 is operable to
rotate about an axis 24. The axis 24 can be the central axis of the
fan 14. In alternative embodiments of the invention, the fan 14 can
be eccentric relative to the axis of rotation. The reinforcing
member 44 contacts a predetermined subset of less than all of the
plurality of blades 32. In the invention, the contact between the
reinforcing member 44 and a subset of less than all the blades is
predetermined.
[0017] In various embodiments of the invention, the reinforcing
member 44 can contact every other blade 32. Alternatively, the
reinforcing member 44 can contact every third or fourth blade 32.
Alternatively, the reinforcing member 44 can contact two adjacent
blades 32 and be spaced from the blades 32 on opposite sides of the
adjacent blades 32. The reinforcing member 44 can contact less than
half of the plurality of blades 32 or more than half of the blades
32. The blades 32 that are contacted are reinforced such that the
reinforced blades 32 have increased stiffness and have a different
frequency than a blade 32 that is not reinforced.
[0018] FIG. 3 is a magnified portion of FIG. 2 and shows a first
embodiment of the invention. Each of the predetermined subset of
blades 32 can be longer along the axis 24 than each of the
remaining blades 32. In FIG. 3, the platform 38 of the blade 32
defines an axially aft edge 48. The reinforcing member 44 and the
edge 48 contact one proximate to an outer diameter 50 of the
reinforcing member 44. The contact between the platform 38 and the
reinforcing member 44 at the edge 48 reinforces and stiffens the
blade 32.
[0019] FIG. 3 also shows an axially aft edge 52 of an adjacent
blade in phantom. The blade defining the edge 52 can be immediately
adjacent to the blade 32 or spaced further about the axis 24 from
the visible blade 32. FIG. 3 shows a gap between the reinforcing
member 44 and the edge 52. Thus, the blade defining the edge 52 is
shorter than the visible blade 32 along the axis 24. Also, the
blade defining the edge 52 is not reinforced and stiffened as the
visible blade 32.
[0020] In the first embodiment of the invention, the reinforcing
member 44 can seal the fan 14. However, as set forth above, a
structure other than a seal plate can be applied to reinforce some
of the blades. It is also noted that the blades can be reinforced
at the forward end, rather than the aft end as shown in the first
exemplary embodiment.
[0021] FIG. 4 shows a second embodiment of the invention. A blade
32a can include an airfoil portion 36a, a platform 38a, and a root
portion 40a. A reinforcing member 44a can include a plate portion
54a operable to seal against the fan 14. The gap between the plate
portion 54a and the platform 38a is permissible and will not
preclude sealing.
[0022] The reinforcing member 44a can also include one or more arms
56a projecting at least partially along the axis 24a. The exemplary
arm 56a extends partially along the axis 24a and radially in part.
Each arm 56a can extend cantilevered from the plate portion 54a to
a respective distal end 58a. The arms 56a of the reinforcing member
44a can contact a radially inward side 62a of platforms 38a of the
predetermined subset of blades 32a. In alternative embodiments, the
reinforcing member 44a could contact the blade 32a radially inward
of the platform 38a, such as at a point 64a.
[0023] The exemplary arm 56a can include a shaft portion 60a
extending from the plate portion 54a. The distal end 58a can be a
protuberance thicker than the shaft portion 60a. The thicker distal
end 58a having greater mass can enhance the stiffness of the blade
32a. However, the arm 56a can have a constant thickness in
alternative embodiments of the invention.
[0024] The exemplary reinforcing member 44a is shown as a unitary
structure wherein the plate portion 54a and the one or more arms
56a are integrally-formed with respect to one another. In
alternative embodiments of the invention, the reinforcing member
44a can be multiple structures formed separately and joined
(releasibly or fixed) in operation. For example, the plate portion
54a can be similar to the reinforcing member 44 shown in FIG. 3 and
another structure defining the arms 56a could be positioned between
the hub and the plate portion 54a.
[0025] A quantity 66a of lubricating material can be positioned
between the reinforcing member 44a and the blade 32a. The quantity
66a can be formed from a solid lubricant material or from any
material having properties that enhance sliding movement between
the arm 56a and the surface 62a. The blade 32a and the reinforcing
member 44a can be movable relative to one another without
compromising the stiffening provided by the reinforcing member 44a.
The lubricant could be a wear coating on one or both of the
reinforcing member 44a and the blade 32a.
[0026] In some embodiments of the invention, the reinforcing member
44a can be resiliently deformed by engagement with the blade 32a
such that a pressing load is generated on the blade 32a. For
example, in the first embodiment shown in FIG. 3, the outer
diameter 50 can be moved along the axis 24 relative to an inner
diameter of the reinforcing member 44 when the fan 14 (shown in
FIG. 2) is installed. This elastic deformation can result in a
pressing load on the platform 38 and enhance the stiffening of the
blade 32. Similarly, in the second embodiment shown in FIG. 4, the
arm 56a can be rotated counter-clockwise (based on the perspective
of FIG. 4) when the fan 14 (shown in FIG. 2) is installed. It is
noted that embodiments of the invention can be applied in any fluid
compression system using blades, in addition to fans as disclosed
above.
[0027] While the invention has been described with reference to an
exemplary embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended claims.
The right to claim elements and/or sub-combinations of the
combinations disclosed herein is hereby reserved.
* * * * *